Going to be buying a pre-owned DateJust this week - any tips/things to look out for/preferred styles/etc?
All I know is I want the traditional jubilee band, white gold bezel, and most likely a flat blue face.

Don't limit yourself to a week, for starters . I would advise you to pick what you like / what style appeals to you, but I would urge you to maybe research which particular model you want and wait for it.

Going to be buying a pre-owned DateJust this week - any tips/things to look out for/preferred styles/etc?
All I know is I want the traditional jubilee band, white gold bezel, and most likely a flat blue face.

It depends on how old the watch is you are considering. If you are certain you want a Jubilee bracelet, make sure you are buying a newer piece that has solid links. The old Jubilee bracelets with hollow links stretch over time and look terrible. If you are going for an older piece that has hollow links go for one with an Oyster bracelet, as they tend not to stretch out at badly and wear better over time.

+3...if you want a piece of quartz jewelery...maybe look at Cartier at least?

Or go for a cheaper mechanical movement with Frederique Constant?

listen to Cylon here... I don't even want to know what a Hermes "watch" costs, but really if you must have a quartz piece such as this there are far better and at the same time more affordable options.... otherwise you're paying a lot of money for a fancy Swatch watch with a big letter "H" on it.

I didn't realize one watch could generate so much hate!! Haha
I thought that even though this watch has an 'H' it is still quite nice.
I'm lucky I'm not much of a watch guy (i think they make my hands look too feminine) if I change my mind I'll check back here for something more SF approved.

well "hate" is a strong word... but anything quartz is already jumping off the cliff... add Hermes to it and you're putting fuel on the fire! why do you believe a watch will make your hands look feminine? certainly that "H" watch wouldn't help in that respect but I'm sure there is a nice style out there that will work well with your overall look, build, etc. the proper watch will be incorporated into your complete style.. not jump out and stand apart (altho' many buy watches for this sole purpose!)

let's hope before one day comes we can stage an intervention...
listen to Cylon here... I don't even want to know what a Hermes "watch" costs, but really if you must have a quartz piece such as this there are far better and at the same time more affordable options.... otherwise you're paying a lot of money for a fancy Swatch watch with a big letter "H" on it.
edit: ok I couldn't resist... it's $2K+ yikes!!!!

Definitely don't buy the Hermes... or if you do, find someone who bought it and buy it second hand after they take the ridiculously huge hit on value. Since they are basically worth nothing... In women's watches, at least, they would retain some value since women don't seem to care about craftsmanship as compared ot brand name (generalizing, I know)...